RAID, which is short for Redundant Array of Independent Disks, is a software or hardware storage virtualization technology which permits a system to employ many hard drives as one single logical unit. In other words, all drives are used as one and the information on all of them is the same. This type of a configuration has two major advantages over using just a single drive to store data - the first is redundancy, so in the event that one drive breaks down, the information will be accessible from the others, and the second is improved performance because the input/output, or reading/writing operations will be spread among multiple drives. There're different RAID types in accordance with how many drives are used, whether reading and writing are both executed from all of the drives concurrently, if data is written in blocks on one drive after another or is mirrored between drives in the same time, and so on. Based on the particular setup, the fault tolerance and the performance may differ.
RAID in Website Hosting
The state-of-the-art cloud web hosting platform where all website hosting accounts are created employs fast SSD drives rather than the standard HDDs, and they operate in RAID-Z. With this setup, numerous hard disk drives work together and at least a single one is a dedicated parity disk. Basically, when data is written on the remaining drives, it's duplicated on the parity one adding an extra bit. This is carried out for redundancy as even in case some drive fails or falls out of the RAID for some reason, the info can be rebuilt and verified thanks to the parity disk and the data stored on the other ones, which means that not a thing will be lost and there will be no service disturbances. This is one more level of security for your info in addition to the top-notch ZFS file system that uses checksums to make sure that all data on our servers is intact and is not silently corrupted.